Mineralogical, Chemical, Geotechnical and Mechanical Investigations of Bafang Lateritic Fine Soils Formed on Basalts (West-Cameroon) for Road Embankment Purpose

Abstract

The present paper treats the relationship between geotechnical parameters and the mineralogical compositions, in order to understand the behavior of the Bafang lateritic fine soils and their efficient use as road embankment materials on the other hand. Thus, the field campaigns have permitted to distinguish two facies of Bafang lateritic fine soils: reddish and yellowish facies. The X-ray diffraction (XRD), the thermo-gravimetry analysis (TGA) and the X-ray fluorescence (XRF) have revealed that the reddish facies contents: kaolinite (53.34% -48.29%); hematite (16.62% - 17.40 %); gibbsite (8.26 % - 16.54%), ilmenite (7.6 % -7.98%), quartz (1.92 % - 4.65 %), illite (2.65% - 1.99 %) and accessories minerals as florencite (1.45%); montmorillonite (0.90 %) and plagioclase (0.69 %); while the yellowish facies is composed of : 65.1 % kaolinite, 11.2 % gibbsite, 9.64 % goethite, 7.02 % quartz, 3.23 % ilmenite and 2.08 % of illite. Their Silica/sexquioxide ratios correspond to those of moderate laterite. The geotechnical and mechanical characteristics have shown that the reddish and yellowish facies are respectively silty clay and sandy silt. They are plastic to very high plastic and moderately clayey to clayey materials. Moreover, they are medium swelling to high swelling. The IBR values more than 40% and the soaked CBR values prove that these materials belong to the S4 bearing capacity class. The minimum values of UCS and Rt are respectively 1.7 MPa and 0.17 MPa. Then, the results of geotechnical and mechanical properties combining to those of XRD, TGA and XRF have demonstrated that the fine lateritic soils with low silica/sexquioxide ratios values (less than 1.6) are suitable for road embankment.

A petrographic, mineralogical, and geochemical characterizations of the lateritic hardpans of Bamendjou in the western region of Cameroon

“…The study area falls within the intertropical zone and consequently is typically marked by the development of a thick weathered mantle resulting from the surface transformation/alteration of the parent rocks of the lithosphere due to the influences of climatic [12]. This weathered mantle is encountered at shallow depths, and even at certain places-it crops out to the surface as blocks of lateritic hardpans resulting from the direct transformation of basalt [21,23]. These all belong to the lateritic hardpans of the Western Highlands of Cameroon, which are located preferably on fissural volcanic effusions [29].…”

Geotechnical Suitability of Soils in Road Construction for Sustainable Development in Tropical Africa: Case of Lateritic Graveled Soils of Bandjoun (West, Cameroon)

“…The main novelty of this study, compared to previous work conducted, respectively, on lateritic gravel soils in Bafang and the northern part of Mount Bangou by Foko Tambo et al [16] and Hyoumbi et al [51], is the specific evaluation of the geotechnical properties of lateritic gravel soils for road construction, as well as the assessment of their ecological impact and their potential for use as a lowcost and environmentally friendly road construction material. Similarly, the lateritic gravel soils in Bandjoun have high CBR bearing ratios, low fines content, and high gravel content compared to the lateritic gravel soils in Bafang in Western Cameroon [51] and the lateritic gravel materials in the northern part of Mount Bangou [16]. This is likely due to the difference in the geo-environmental formation of these lateritic graveled materials.…”

Assessment of Soils Developed on Various Formations in Maroua (Far North, Cameroon) for Production of Compressed Earth Bricks

“…SiO 2 reflects the presence of quartz and aluminosilicates [41]. The content of Al 2 O 3 within a clay particle depends on the intensity of hydrolysis [42]. Moreover, the amounts of Fe 2 O 3 associated with TiO 2…”